In case anyone was interested, this is my final code for this simple test.
* =================================================================== *
CARDASM HEADER VERSION='1.0',AUTHOR='DLC',DATE='(C)DEC25', X
BASE=10,SVAREA=SAVEAREA
* ------------------------------------------------------------------- *
IF R1,(NE,CR),R10 IF THERE IS AN EXEC PARM
L R1,0(,R1) GET ADDRESS OF EXEC PARM AREA
IF DLMLEN,(NL,CLC),=H'6',AND,=C'DLM=',(EQ,CLC),DLMKWD
MVC DLM,DLMVAL GET CUSTOM DELIMITER
ENDIF END IF
ENDIF END IF
DROP R1 EXEC PARM NO LONGER NEEDED
*
OPEN CARDIN,LINEOUT OPEN SEQUENTIAL DTFS
GETCARD DOLOOP READ CARDS UNTIL EOD
GET CARDIN GET A CARD
IF =C'/&&',(NE,CLC),CARD_IA IF NOT EOJ
AND DLM,(NE,CLC),CARD_IA AND NOT EOD
DATAIN DS 0H ACCEPT INPUT (AND /* EOF)
* LHI R2,128 IF READ LENGTH IS NEEDED
* SH R2,CARDIN SUBT. CCB RESIDUAL COUNT
TR CARD_IA,TRTABLE XLATE NULLS TO SPACES
MVC LINEDATA,CARD_IA SEND INPUT CARD
PUT LINEOUT TO OUTPUT DEVICE
ENDIF END IF
UNTIL =C'/&&',(EQ,CLC),CARD_IA, LOOP UNTIL EOJ X
OR,DLM,(EQ,CLC),CARD_IA OR EOD
* ------------------------------------------------------------------- *
ENDIN DS 0H END OF CARD INPUT
CLOSE LINEOUT,CARDIN CLOSE SEQUENTIAL DTFS
XR R15,R15 ZERO RETURN CODE
EXIT DS 0H PROGRAM EXIT
TRAILER RETCODE=R15,SVAREA=SAVEAREA
* =================================================================== *
Sincerely,
Dave Clark
--
int.ext: 91078
direct: (937) 531-6378
home: (937) 751-3300
Winsupply Group Services
3110 Kettering Boulevard
Dayton, Ohio 45439 USA
(937) 294-5331
On Mon, Dec 15, 2025 at 1:48 PM David Clark <[email protected]> wrote:
> Nevermind. I was off in my calculation of the CCB address. This is the
> CCB--and, yes, the residual count looks correct. Thanks.
>
> 0030C200 0D000000 00500320 00500328
>
> Sincerely,
>
> Dave Clark
> --
> int.ext: 91078
> direct: (937) 531-6378
> home: (937) 751-3300
>
> Winsupply Group Services
> 3110 Kettering Boulevard
> Dayton, Ohio 45439 USA
> (937) 294-5331
>
>
> On Mon, Dec 15, 2025 at 1:32 PM David Clark <[email protected]> wrote:
>
>> >> The first 16 bytes of the DTF is a CCB. One of the 16-bit fields in
>> the CCB is the residual count.
>>
>> Then I am confused, because it looks like the CCB, in my case, is as
>> follows after reading the first card. The compile listing also seems to
>> say that the first two bytes are the residual count. If that is correct,
>> did I read 80? ...or did I read only 48? This seems reversed. However,
>> the 7th half-word would be right.
>>
>> 00500300 00500340 00066150 00308200
>>
>>
>> CARDIN DTFCD DEVADDR=SYSRDR,DEVICE=3505,IOAREA1=CARD_IA,BLKSIZE=128, X
>> ERROPT=IGNORE,EOFADDR=DATAIN
>> +* IOCS AND DEVICE INDEPENDANT I/O - DTFCD -5686-007-02-C440 @U31TUJS
>> +* 5686-007 (C) COPYRIGHT IBM CORP. 1981,1989 @U31TUJS
>> +* LICENSED MATERIAL - PROGRAM PROPERTY OF IBM @D149DBF
>> + DC 0D'0'
>> +CARDIN DC X'000082000000' RES. COUNT, COM. BYTES STATUJJ
>> + DC AL1(0) LOGICAL UNIT CLASS
>> + DC AL1(0) LOGICAL UNIT
>> + DC A(IJCX0017) CCW ADDRESS @D33FDVS
>> + DC 4X'00' CCB-ST BYTE,CSW CCW ADDR.
>>
>> Sincerely,
>>
>> Dave Clark
>> --
>> int.ext: 91078
>> direct: (937) 531-6378
>> home: (937) 751-3300
>>
>> Winsupply Group Services
>> 3110 Kettering Boulevard
>> Dayton, Ohio 45439 USA
>> (937) 294-5331
>>
>>
>> On Mon, Dec 15, 2025 at 12:12 PM Charles Mills <[email protected]> wrote:
>>
>>> 50-year-old memory so take this with a grain of salt: The first 16 bytes
>>> of the DTF is a CCB. One of the 16-bit fields in the CCB is the residual
>>> count. So if the DTF is expecting 128 bytes and reading 80, the field will
>>> contain 48 = x'0030'.
>>>
>>> But I would think that scanning for binary zeroes or translating them to
>>> blanks would be a perfectly acceptable approach.
>>>
>>> Charles
>>>
>>>
